r either roads or bridges. Every one is left to take care of
himself, and get over them as he best may. It is only now and then that
positive necessity prompts to a great effort, and then a road is
repaired or a broken bridge patched with new ropes.

But the road that was travelled by Don Pablo had seen no repairs--there
were no bridges. It was, in fact, a mere pathway where the traveller
scrambled over rocks, or plunged into the stream, and forded or swam
across it as he best could. Sometimes it lay along the water's edge,
keeping in the bottom of the ravine; at other places no space was left
by the water, and then the path ascended and ran along some ledge
perhaps for miles, at the end of which it would again descend to the bed
of the stream.

CHAPTER XII.

ENCOUNTER UPON A CLIFF.

That night they encamped in the bottom of the ravine close to the
water's edge. They found just enough of level ground to enable them to
stretch themselves, but they were contented with that. There was nothing
for the animals to eat except the succulent, but thorny, leaves of the
_Cactus opuntia_, or the more fibrous blades of the wild agave. This
evening there were no quinoa seeds to be had, for none of these trees
grew near. Even the botanist, Don Pablo, could find no vegetable
substance that was eatable, and they would have to sup upon the vicuna
meat, without bread, potatoes, or other vegetables. Their stock of ocas,
ullucas, and macas, was quite out. They had cooked the last of the macas
for that morning's meal.

Guapo here came to their relief. Guapo's experience went beyond the
theoretical knowledge of the botanist. Guapo knew a vegetable which was
good to eat--in fact, a most delicious vegetable when cooked with meat.
This was no other than the fleshy heart of the wild maguey (_agave_),
with part of the adhering roots. Among naked rocks, in the most barren
parts of the desert wilderness, the wild agave may be found growing in
luxuriance. Its thick, succulent blades, when split open, exude a cool
liquid, that often gives considerable relief to the thirsty traveller;
while the heart, or egg-shaped nucleus from which spring the sheathing
leaves--and even parts of the leaves themselves--when cooked with any
sort of meat, become an excellent and nourishing food.

The Indians make this use of the aloe on the high plains of Northern
Mexico, among the roving bands of the Apache, Navajo, and Comanche.
These people cook them al